Kommentar zu Wajikra 13:36

'והנה פשה הנתק בעור וגו, “and behold if the scall be spread in the skin, etc. טמא הוא, “he is ritually contaminated.” This entire verse appears superfluous; we had already read that “if the scall did not spread out on the afflicted person the priest will declare him ritually clean, (verse 35)” is ritually contaminated clean (remains that way). If you were to argue that if not for this verse, I would give a different interpretation to our verse here namely” “if the scab spread and there is no single black hair he remains ritually contaminated, but if there is only one such symptom, namely the spreading out of the scall, this would not result in the person under discussion becoming declared ritually contaminated, or as the case maybe, to become ritually contaminated.